More than 30,000 people have been displaced within rebel-held northwest Syria due to bombardment by government and allied forces which began last week, a United Nations official said on Monday. UN office spokesman David Swanson says that as of September 9, 30,542 people have been displaced from northwest Syria, moving to different areas across Idlib. Damascus, backed by allies Russia and Iran, has been preparing a major assault to recover Idlib and adjacent areas of northwest Syria from rebels. The area is Syria's last major stronghold of active opposition to the rule of President Bashar al-Assad. About 3 million people live in the opposition-held area, which comprises most of Idlib province and adjacent small parts of Latakia, Hama and Aleppo provinces. Swanson said that since Friday mortar and rocket attacks had increased, especially in the northern Hama countryside and southern Idlib rural areas. He said 47 per cent of those displaced have moved to camps, 29 per cent are staying with families, 14 per cent have settled in informal camps and 10 per cent are in rented accommodation. Australian Associated Press